Makers of the holding tanks that many Ericson Owners possess.
www.ntotank.com
//sse
Just a comment about Ronco. It's really great that they have the drawings and specs from more than thirty years ago, and can whip up a holding tank in just a few days. But - you have to monitor them closely, and you can't assume that they will do it right. I wanted my E34 tank modified to have the two output ports
on top of the tank, with internal pipes to pick the stuff off the bottom. I also wanted a bigger vent opening. Well, despite all of my information and drawings, they managed to get it wrong. I was able to work around their mistakes but, still, it was annoying. So my advice is: make sure as you can that they understand what is wanted.